1. Field of the Invention
This invention relates to improvements in a side door hinge mechanism in a motor vehicle through the utilization of a quadric rotary link mechanism.
2. Description of the Related Art
In most cases, the side door in a motor vehicle, e.g. passenger car has heretofore been installed in a manner to be rotatable about a hinge affixed to a vehicle body for opening or closing. In order to allow an occupant of the motor vehicle to open or close the side door for getting in or out of the motor vehicle, a door opening angle commensurate to the total length of the side door is required. At this time, when a space outwardly of the motor vehicle is small, there are many cases where it is difficult for the occupant to get in or out of the vehicle because the side door cannot be opened sufficiently.
In contrast thereto, as disclosed in Japanese Utility Model Laid-Open (Kokai) No. 46014/1982 or 101263/1980 for example, there has been proposed a side door hinge mechanism through the utilization of a quadric rotary link mechanism, wherein the quadric rotary link mechanism comprises: a rotary link interconnecting a point on a body of a vehicle and another point on a side door as rotary centers out of two points spaced apart from each other on the body and two points spaced apart from each other on the side door; another rotary link interconnecting the other point on the body and the other point on the side door as being centers; a portion between the two rotary centers on the body; and another portion between the two rotary centers on the side door.
The side door hinge mechanism utilizing the above-described quadric rotary link mechanism makes it possible for the occupant to reduce the necessary space outwardly of the motor vehicle while securing a space at his feet. In consequence, even when the space outwardly of the motor vehicle is small, the occupant can get in or out of the motor vehicle by opening or closing the side door.
In the side door hinge mechanism utilizing the above-described quadric rotary link mechanism, the rotary center shaft of the side door is spaced apart by a rotary link's length from the rotary center shaft of the body, whereby a moment acting on the side door hinge due to a load of the side door becomes high and also a high load due to this moment is applied to a portion for mounting the rotary center shaft of the side door.
In consequence, in order to increase the rigidity for supporting the side door, it is necessary to mount a plurality of door hinges arranged in the vertical direction.
However, when the plurality of side door hinges are mounted in the vertical direction as described above, such disadvantages are presented that these rotary center shafts need to be aligned with each other in the vertical direction and the works of mounting and adjusting are troublesome.
Further, the rigidity of the surfaces of the body and the side door, to which the above-described rotary center shafts, particularly, the rigidity of the surface of the side door should be made considerably high. To satisfy this requirement, such a disadvantage is presented that the weights of the side door and of the door hinge should be increased.
More specifically, if the rigidity of the side door is low, then, in conjunction with the long length of the door hinge, i.e. the rotary link, for example the rigidity in the vertical direction, torsional rigidity and rigidity for bearing an excessive opening of the side door when the side door is opened become low, such disadvantages are presented that the side door is displaced downwardly, distorted or deformed when fully opened.
Further, if the rigidity is low when the door is closed, such a disadvantage is presented that ill-fitting to the body occurs.
With the side door hinge utilizing the quadric rotary link devices as described above, a high rigidity is required, and consequently, both the shape and the weight thereof should be large.
However, if such a side door hinge as described above is disposed between the forward end of the side door and the vehicle body, then a member having a rigidity of a required level is secured in a small space, and consequently, the side hinge is arranged in the space with high density.
Here, in general, a power source to the power window regulator and a wire harness for the control in the side door, for example, are disposed between the forward end of the side door and the vehicle body. However, when the members are arranged in the small space with high density as described above, such a disadvantage is presented that it becomes difficult to secure a space, into which the wire harness is arranged.
Here, for increasing the rigidity, it is proposable that a side door hinge mechanism in a motor vehicle comprising:
a pair of top rotary center shafts on the side of a side door, spaced apart from each other in the generally horizontal direction and supported on an end portion of the side door on the side of a rocking proximal end at an upper portion thereof;
a pair of top rotary center shafts on the side of a vehicle body, spaced apart from each other in the generally horizontal direction and supported on a surface at an upper portion thereof on the side of the vehicle body, and disposed adjacent said end portion;
four bottom rotary center shafts aligned with said top rotary center shafts and positioned downwardly thereof;
a top control arm rotatably connected at opposite ends thereof to one of the top rotary center shafts on the side of the vehicle body and one of the top rotary center shafts on the side of the side door out of said top rotary center shafts;
a bottom control arm rotatably connected at opposite ends thereof to said bottom rotary center shafts aligned with said top rotary center shafts at the opposite ends of said top control arm; and
a main arm formed integrally in the vertical direction and rotatably connected at end portions thereof in the vertical and the lateral directions to the top rotary center shafts and the bottom rotary center shafts at the other side.
The rotary center shafts for supporting the vertically integral main arm in the above-described side door hinge mechanism, particularly, the top rotary center shafts and the bottom rotary center shafts on the side of the vehicle body may be formed into a continuously integral form in the vertical direction and extended through an end portion of the main arm on the side of the vehicle body.
However, when the above-described continuous and vertically integral rotary center shaft is extended through the main arm, such disadvantages are presented that the mounting works become troublesome and the side door hinge mechanism is increased in weight and cost.
Now, in order to prevent an excessive opening when the side door is fully opened, it is necessary to form a stopper or a stopper contact surface on the side of the side door or the vehicle body.
As an example of a stopper construction in the side door hinge mechanism utilizing the quadric rotary link devices as described above, there is one wherein a stopper is formed on a bracket mounted to the vehicle body and a link member provided on one side is adapted to abut against this stopper as described in Japanese Utility Model Post-Exam Publn (Kokoku) No.
However, since the stopper in the above-described side door hinge mechanism is formed at a position spaced apart from a portion of the vehicle body where the bracket is mounted to the vehicle body, the stopper tends to be deformed relative to the portion of the vehicle body where the bracket is mounted to the vehicle body while the side door is frequently opened and closed.